(no subject)

From: Lee Humphrey (Lockheed-Martin  Corporation)
To: Kurtis Anliker (Hughes Air Warfare Center), RP-ML
Date: Wednesday, February 1, 1995
Kurt,
I have seen messages like you have indicated on my 250 with the 386 
controller both before and after the PCU.  I am running the regular 
laser with 5149 resin.  There are/were several causes.  One cause is 
resin condenses and cures in selective spots on the optical window.  
Correction for this was cleaning and increasing the chamber 
temperature 1 degree C.  The other major cause was oscillation and/or 
power drop.  For us, it preceeded a laser and power supply changeout.  
It was difficult to determine which component took out the other 
although I strongly suspected the power supply.  If the sensor picks 
up a large variance it will continue to do what you indicate until the 
variance clears or part completes.  I had a laser tuned in the middle 
of a part build and the increase in power caused the error warning 
every layer, adding to build time as well as the build.log although 
nothing was actually wrong at that time. You may want to try to clean 
the optical window and sensors (carefully, check with Field Engineer 
if neccessary) and look at the beam power as a function of time as 
well as the drift from default position.
Good Luck
Please keep rp-ml updated to your findings.

Lee Humphrey
Martin Marietta Electronics & Missiles Systems
E-Mail: Lee_Humphrey@ccmail.orl.mmc.com